Should You Turn Off the Engine at Traffic Lights?
3 Answers
Whether to turn off the engine at traffic lights depends on the situation. If the waiting time exceeds 1 minute, the engine should be turned off. Otherwise, it is not necessary. Here is some information about turning off the engine at traffic lights: 1. Wear and Tear: For daily use, these effects are negligible. The engines in typical household cars are generally designed to handle over 50,000 starts. Based on the frequency of turning off the engine during normal use, even after 10 years, the number of starts would still be far below the 50,000-start lifespan. 2. Duration of Shutdown: Restarting the engine immediately after turning it off consumes more fuel than idling. However, if the engine is turned off for more than 10 seconds or longer, the fuel consumption during restart is equal to or even less than idling, which is beneficial for the car.
As a frequent city driver, I often contemplate whether to turn off the engine at red lights. Briefly shutting it off does save some fuel and reduce exhaust emissions, which benefits the environment. I've found that if the red light lasts over 30 seconds, turning off the engine may save 1% of fuel—small savings add up to reduce carbon footprint. However, in practice, restarting the car increases strain on the starter battery, shortening its lifespan. During peak hours, when lights change too quickly, I rarely turn off the engine to avoid delaying acceleration or causing traffic congestion. From personal experience, this practice is only feasible with long red lights in big cities or in cars with auto start-stop systems—otherwise, frequent operation isn’t worth it. In winter or summer, shutting off the engine cuts off AC or heating, making the cabin uncomfortable, so I recommend doing this only for red lights expected to exceed 30 seconds. Overall, this habit requires balancing fuel savings and maintenance costs.
I've been driving for almost 20 years since my youth and have seen many people turn off their engines at red lights. Theoretically, this saves a bit on fuel costs, but if the red light is too short, like under 15 seconds, turning off and restarting the engine actually wastes fuel because the engine cools down just as it's warming up, consuming more energy. Over time, it also wears out the starting system, potentially leading to additional repair costs. From my personal experience, older car batteries can't handle frequent starts and will fail faster, so it's better to keep the engine idling. In cities, where red lights average 10-20 seconds, it's simply unnecessary; only consider it if the light lasts over 45 seconds, and even then, it depends on the car model—manual cars are prone to rolling back. I recommend beginners start with the basics, understand their car's condition, and then decide. Overall, the fuel savings are minimal, but safety comes first—don't risk big losses for small gains.
